Hamtaro: Rainbow Rescue was released in Japan and Europe, but had its North American release cancelled with no reason given. The distribution of the game outside of Japan was convoluted, and copies of it in English are overall scarce.
The game's core gameplay consists of navigating a fairly expansive world, whose hub is the hamsters' Clubhouse. Throughout these locations, the player is faced with several minigames, most of them with an unique mechanic, and winning a challenge nets the player collectible stickers, of which there are 451. The catch, however, is that each minigame can only be player by a specific character, which often have to be found in some part of the level by means of exploration and fulfilling tasks.
The structure of the levels emphasizes the small size of the hamsters, with brooms and desks often being used as makeshift ladders, for examples. Enemies are portrayed as bigger animals, such as chicks and snakes. Objects such as rocks also present substantial obstacles for the hamsters to overcome. By combining forces, it is possible for them to get through such situations.
It features a very substantial post-game segment, with an entire optional quest to be completed, and many stickers are impossible to get over the course of the main story. On top of that, painting features are available, and the stickers can be arranged at will on the many backgrounds that can be collected throughout the game.
The playable Ham-Hams are Hamtaro, Bijou, Oxnard, Boss, Cappy, Maxwell, Pashmina, Penelope, Panda, Stan, Sandy, Howdy, and Dexter.